Back to Blog

The Impact of Iron and Ferritin on Hypothyroidism: Understanding the Connection

hashimoto's hypothyroidism iron low ferritin
photo of mallet pounding hot iron

Hypothyroid patients classically have low ferritin and other low iron levels - just another negative side effect of undiagnosed, untreated, or mistreated hypothyroidism. Iron provides life-affirming oxygen to organ systems through its role in red cell production. Iron is an essential protein component for metabolism (low iron levels often go hand in hand with low B12 results). Without adequate iron, muscles lose their tone and elasticity. Low iron can compromise brain function: oxygen supply in the blood is assisted by iron, and the brain uses approximately 20% of the blood oxygen. Proper flow of blood in the brain stimulates cognitive activity.

Ferritin is “iron storage”; it is important to the amount of iron available in the body. Ferritin acts as a buffer against both iron deficiency and iron overload. It stores iron in a non-toxic way, deposits it in a controlled fashion, and then transports it to areas where it is needed. T4 has a hard time converting to T3 when low levels of ferritin are present. 

Deficiency Symptoms (Some symptoms mimic hypothyroid symptoms.)

• Light-headedness/dizziness

• Restless legs

• Heart palpitations (especially upon laying down)

• Shortness of breath

• Feeling like you cannot take a deep enough breath or get enough air

• Exhausted easily/low energy

• Poor recovery after physical exercise

• Weak limbs

• Brain fog/inability to focus

• Feeling stressed/overwhelmed

• Anxious and easily irritated

• Numbness in hands

• Female orgasm contractions feel “weak” and not as strong as before

• Not enough vaginal moisture when aroused (or different consistency than before) 

Why Might A Deficiency Occur From Hypothyroidism?

Being hypothyroid has a cascade of negative effects on the body - one of which can be loss of iron. There are a variety of potential factors. Hypothyroid women might have heavier periods due to thyroid hormones’ effect on sex hormones which can create imbalances. Lower production of stomach acid in hypothyroid patients can lead to iron absorption issues. Inflammation in general from being Hypothyroid or having Hashimoto’s hypothyroidism…or inflammation from food unknown sensitivities to certain foods like gluten and dairy, etc.

Where to Get Iron?

Food sources include meats, organ meats (like liver), green leafy vegetables, blackstrap molasses, and eggs. Cooking foods in a real cast iron skillet also helps. Sometimes food does not work in raising iron effectively, and one must take an iron supplement - this is often the case with hypothyroid patients.


Because inflammation can throw off a ferritin test and make it appear normal, or even high, getting a comprehensive iron panel will be most effective. Below are optimal levels.

  • Ferritin: For both men and women 50–100 (if working with a common reference range of 10–150). Ferritin over 100 can indicate inflammation in the body or indicate ingesting too much iron. High-quality omega-3 fish oil and krill oil can help reduce high ferritin and inflammation. (If you are allergic to shellfish as I am, you may need to avoid krill oil.)
  • Total Iron Binding Capacity (TIBC): With healthy levels of iron, this will be low in the range, about one quarter above the bottom number in the range you are using (common range is 250–450). TIBC measures whether a protein called transferrin has the capacity to carry iron in the blood. If your result is high, and in the absence of chronic disease, you might be anemic.
  • Serum Iron (amount of circulating iron): Around 110 for women, 130 for men (common reference range is 35–155).
  •  % Saturation (serum iron divided by your TIBC): Women usually score around 35% and men 40%-45% (common reference range is 15%-55%).


There are various forms of iron (ferrous sulfate, ferrous bisglycinate, ferrous gluconate, ferrous fumarate, etc.). After having several issues with iron over the years and trying various forms of iron, my favorite form is ferrous bisglycinate chelate, always taken with food (and preferably with vitamin C because it helps with absorption).

This form of iron did not constipate me at all, but if for some reason you feel your bowels are sluggish while taking iron, you can always look into taking 400–800 mg of magnesium nightly. Heads up: Supplementing with iron will turn your stools black in color, and you might notice a tar-like consistency/appearance. This is normal!

Iron Supplementation Guidelines

How much iron do I need to take to correct low ferritin and iron deficiency, and for how long?

When my ferritin got down to 10 (in a reference range of 10–150) and I was riddled with restless legs and many other low iron symptoms, I used the Blue Bonnet brand. I had to take three 27mg pills per day for about 3 months (1 pill at lunch and 2 pills at dinner) to optimize my levels (while I was also getting optimized on thyroid hormone replacement).

It can take anywhere from four to twelve-plus weeks to optimize your ferritin levels, depending on how low they were to begin with. If levels are not severely low, sometimes a daily multivitamin with iron can bring up levels in four to six weeks. Once iron is optimized, it might benefit menstruating females to take a multivitamin with iron daily on a few of their menstrual bleeding days.

Should I avoid anything while taking iron?

Avoid taking calcium with iron, and avoid taking iron with thyroid hormone replacement (iron can bind with the thyroid hormones, rendering them less effective). Ideally, make sure you take your thyroid hormones and iron two to four hours apart. Take thyroid hormones an hour before taking iron, or several hours after taking iron.

How often do I get my iron levels tested?

If you are deficient and need to increase your your levels, testing every four weeks is conservative and can help avoid overloading on iron, which can be toxic.

About the author:  Elle Russ is a #1 bestselling author, world-renowned thyroid health expert, and master coach. Take her Free Thyroid Masterclass HERE

Sign Up For My Newsletter!

I hate SPAM. I will never sell your information, ever.